What do You Know about Salivary Acid?

　　In 2020, the "Simba bird's nest fake sale incident" was widely discussed, and one of the important bases of the incident was that the salivary acid content of bird's nest in the test report was only 1.4‱, while the "Bird's nest quality grade" (GH/T 1092-2014) stipulates that the salivary acid content in dried bird's nest should be at least ≥5%, the test results of Simba's bird's nest are contrary to the relevant standard regulations.

　　So, what is sialic acid? What is the function of salivary acid? What are the regulations of salivary acid application in each country? For this reason, Food Partner has compiled a list of salivary acid for your reference.

　　First, What is salivary acid

　　Sialic acid (SA), scientifically known as "N-acetylneuraminic acid", is a class of acidic nine-carbon monosaccharide, which is the general name of all N- or O-derivatives of neuraminic acid or ketonyl-deoxynonitrullose acid (KDN).

　　It was originally isolated by scientist Gunnar Blix from protein hydrolysates in bovine mandibular salivary glands, hence the name sialic acid. As a naturally occurring carbohydrate, it is widely distributed in living organisms and can form different polymers, complexes and play important physiological functions in the life activities of living organisms. Its main food source is breast milk, but it is also present in foods such as bird's nest, milk, goat's milk and cheese.

　　Second, what is the function of salivary acid

　　In living organisms, the expression of genetic information is passed from DNA to RNA, and then from RNA to protein, which in turn completes the complex life activities. Sialic acid can be combined with proteins and lipids to complete the glycosylation modification of proteins, and then play a biological effect, and this "combination" is called sialic acid modification. Based on this biological effect of sialic acid, it can be used in food, health food and medicine.

　　In food and health food, since sialic acid is a structurally and functionally important component of brain gangliosides and glycoproteins, it is similar to DHA (docosahexaenoic acid), so it can be used as an important supplement for early brain development of infants, but there are no clear regulations on whether sialic acid can be used in infant food.

　　In terms of antiviral, studies have shown that sialic acid has significant effects in fighting influenza virus, polyomavirus and rotavirus. The mechanism is that viral infection of host cells begins with the attachment of glycosyl receptors on the surface of the host cell through the glycan chains on the viral capsid, most of which have sialic acid terminal binding sites. Free sialic acid or its derivatives in the organism can block these bindings and thus may have an antiviral effect.

　　In terms of immunity, sialic acid has an effect on the entire immune system of the organism because it is not degraded by digestive enzymes in the intestine and the glycoprotein has a good adjuvant effect against pathogens and improves the immune system's ability to recognize viral bacteria.